1. Field of the Invention
The invention relates to a bearing system and a cage for a bearing.
2. Description of Related Art
When a bearing is exposed to a vibration, a force of inertia may be so great as to cause fatigue cracks in the cage after a period of time, which may finally lead to an damage to the whole bearing.
At present, a conventional method of monitoring an operating condition of the bearing is to use a corresponding sensor fixed to an outer race of the bearing to measure a vibration or temperature of the bearing. As shown in FIG. 1, the bearing includes an outer race 1a, an inner race 2a, a roller 3a and a cage 4a, and an acceleration/temperature sensor 5a is disposed on the outer race 1a for measuring the vibration or temperature of the bearing. According to the measured abnormal vibration level or high temperature, a bearing failure in the inner race, the outer race or the roller of the bearing may be detected.
However, for cracks in the cage in an early stage, this vibration or temperature measuring method is not always effective, and for monitoring of the cracks in the cage in the early stage, this vibration or temperature measuring method is not a reliable monitoring method. In most of cases, the cage of the bearing is still required to be checked manually.
Moreover, the bearing cage is generally only a mechanical part, and generally, there is no sensor on this part. The bearing cage itself cannot provide any information about its operating condition. In the early stage when the cracks appear in the bearing cage, the measurement of the vibration or temperature of the bearing also fails to effectively give information of a cage failure. Once the cage begins to have a small crack, a damage process of the cage is very fast. Sometimes, it is too late when the vibration or temperature of the bearing reaches a warning level. The measurement of the vibration also suffers from an environment influence. In addition, to check the condition of the bearing manually, the bearing is required to be dissembled, which is very time consuming and thus makes a late maintenance cost of the bearing very high